Custom Firmware Unlocks Fitness Tracker

July 3, 2016 by Elliot Williams 17 Comments

[Mikhail] sent us a teaser video for a hack he’d done (embedded below). He takes a Bluetooth LE fitness tracker dongle and reflashes it spit out the raw accelerometer data and trigger events. He then wrote a phone app that receives the data and uses the device as an alarm, an on/off switch, a data-logging device, and more.

We thought it was cool enough that we asked [Mikhail] for more detail, and he delivered in spades! Inside the device is a Nordic NRF51822, their ARM Cortex + Bluetooth chip, an accelerometer, and a bunch of LEDs. [Mikhail] mapped out the programming headers, erased the old flash, and re-filled it with his own code. He even added over-the-air DFU re-flashing capability so that he wouldn’t have to open up the case again.

Continue reading “Custom Firmware Unlocks Fitness Tracker” →

Mechanical Horse-Bike

July 2, 2016 by Elliot Williams 18 Comments

Oh [Rodger Cleye]! You had us at “unicycle, duct tape, styrofoam, and tie wraps”. But watching the horse-bike in action (video below) is just about enough for us to go out and make one ourselves. (For our child, naturally. We’re far too dignified.)

If you trawl around [Rodger]’s YouTube channel, you’ll see no end of odd motorized vehicles. Like last year’s motorized horse project, or this stormtrooper speeder. But there’s just something about the way that the horse’s legs move along with the rider that is slightly more enchanting. (That’s the “unicycle” part of the build.) And, we assume, the rider gets a little bit more exercise to boot.

We’ve featured a few builds of [Rodger]’s before, including his motorized couch build that’s obviously controlled from the seat-mounted coconut, and of course a pneumatic Boba Fett rocket.

Horrible Macro Rig Makes Good Photos

July 1, 2016 by Elliot Williams 19 Comments

We love horrible hacks like this. It’s a lens and a ring of LEDs, taped to a cell phone. Powered through crocodile clips, also taped to the cell phone. There’s nothing professional here — we can think of a million ways to tweak this recipe. But the proof of the pudding is in the tasting.

Continue reading “Horrible Macro Rig Makes Good Photos” →

What Could Go Wrong: SPI

July 1, 2016 by Elliot Williams 58 Comments

Serial Peripheral Interface (SPI) is not really a protocol, but more of a general idea. It’s the bare-minimum way to transfer a lot of data between two chips as quickly as possible, and for that reason alone, it’s one of my favorites. But that doesn’t mean that everything is hugs and daffodils. Even despite SPI’s simplicity, there are still a few ways that things can go wrong.

In the previous article in this series, inspired by actual reader questions, I looked into troubleshooting asynchronous serial connections. Now that you’ve got that working, it’s time to step up to debugging your SPI bus! After a brief overview of the system, we’ll get into how to diagnose SPI, and how to fix it.

Continue reading “What Could Go Wrong: SPI” →

200W Laser Bazooka Is Just Silly

June 30, 2016 by Elliot Williams 79 Comments

We weren’t going to run this one, because, well, it’s just ridiculous. But enough of you have browbeat us by sending in tips to the tipline that we’re going to capitulate. We’re not going to name you all by name, because really, you should be ashamed of yourselves. But you know who you are!

[Styropyro] does a lot of crazy things on YouTube. We really liked his “stuff in a microwave oven” series. He’s also obsessed with lasers and popping black balloons. So he took the laser heads out of four DLP computer projectors (the ones with 24 of those 1.5W Nichia diodes) and combined them. Yup, 200W of ~~405~~ 445nm blue.

Then he just straps them together and passes them through a lens. It’s not a tight beam, but this thing is really bright. Even though the beam is very loosely focused, it burns stuff. That’s about all you can say. Lots of laser. Boy Howdy!

OK, there, we ran it. Don’t do this at home. It doesn’t require much finesse, and it’s going to get someone blind. Much better to expend your efforts on something more civilized like a projector. At least then you can play vector games on the wall. And stay off my lawn!!! (Kids these days…)

For those that do want to burn stuff, [Joshua Vasquez] published an article yesterday about building a safe laser cutter… much more worth your energy than anything billed as a laser bazooka.

Continue reading “200W Laser Bazooka Is Just Silly” →

The EAGLE Has Landed: At Autodesk!

June 29, 2016 by Elliot Williams 82 Comments

The selloffs continue at Farnell! We’d previously reported that the UK distributor of electronics parts was being sold to a Swiss distributor of electronics parts. Now it looks like they’re getting rid of some of their non-core businesses, and in this case that means CadSoft EAGLE, a popular free-for-limited-use PCB layout suite.

But that’s not the interesting part: they sold EAGLE to Autodesk!

Autodesk had a great portfolio of professional 3D-modeling tools, and has free versions of a good number of their products. (Free as in beer. You don’t get to see the code or change it.) By all accounts, the professional versions of their tools are very professional if you can afford them, and the trial versions are still useful. This makes EAGLE slot very nicely into their business model, filling a hole (PCB design) in their toolchain.

What does this mean for those of you out there still using EAGLE instead of open-source alternatives? (We haven’t used EAGLE since KiCAD got good a couple years back.) Beats us! Care to speculate wildly? That’s why we have a comments section. Go! In the mean time we hope to have more info for you directly from Autodesk soon so stay tuned to the front page.

E Pluribus Unix, QR-Style

June 28, 2016 by Elliot Williams 9 Comments

It’s been a long time since we’ve logged into a UNIX mainframe (other than our laptop) but one of our fond memories is the daily fortune: small, quirky, sometimes cryptic sayings that would pop up on the login screen if your system administrator had any sense of humor.

Apparently, we’re not alone. [Alastair] made his own fortune clock which gives you a new “fortune” every second instead of every login. There’s a catch, of course. It’s a QR clock — the fortune is encoded in a QR code instead of being displayed in human-readable form. You have to take a picture of the tiny OLED screen to know what it says. (Watch it sending him Shakespeare sonnets in the video below.)

You probably know QR codes are good for conveying URLs, but their use as general-purpose text containers is underappreciated in our book, so we’re glad to see this example. Now, we’ve seen QR clocks before (here, and here), and this version does have the disadvantage that you can actually tell what time it is. But we’re grateful for the trip down memory lane.

Continue reading “E Pluribus Unix, QR-Style” →